literalt aig_prop_baset::land(literalt a, literalt b)
{
if(a.is_true()) return b;
if(b.is_true()) return a;
if(a.is_false()) return a;
if(b.is_false()) return b;
if(a==neg(b)) return const_literal(false);
if(a==b) return a;
return dest.new_and_node(a, b);
}
literalt aig_prop_baset::lxor(literalt a, literalt b)
{
if(a.is_false()) return b;
if(b.is_false()) return a;
if(a.is_true()) return neg(b);
if(b.is_true()) return neg(a);
if(a==b) return const_literal(false);
if(a==neg(b)) return const_literal(true);
// This produces up to three nodes!
// See convert_node for where this overhead is removed
return lor(land(a, neg(b)), land(neg(a), b));
}
tvt cvc_convt::l_get(literalt l) const
{
if(l.is_true()) return tvt(true);
if(l.is_false()) return tvt(false);
assert(l.var_no()<boolean_assignment.size());
return tvt(boolean_assignment[l.var_no()]^l.sign());
}
tvt z3_propt::l_get(literalt a) const
{
tvt result=tvt(false);
std::string literal;
Z3_ast z3_literal;
size_t found;
if(a.is_true())
return tvt(true);
else if(a.is_false())
return tvt(false);
literal = "l"+i2string(a.var_no());
map_prop_varst::const_iterator cache_result=map_prop_vars.find(literal.c_str());
if(cache_result!=map_prop_vars.end())
{
//std::cout << "Cache hit on " << cache_result->first << "\n";
z3_literal = cache_result->second;
Z3_app app = Z3_to_app(z3_ctx, z3_literal);
Z3_func_decl d = Z3_get_app_decl(z3_ctx, app);
literal = Z3_func_decl_to_string(z3_ctx, d);
found=literal.find("true");
if (found!=std::string::npos)
result=tvt(true);
else
result=tvt(false);
}
if (a.sign()) result=!result;
return result;
}
tvt satcheck_minisat2_baset<T>::l_get(literalt a) const
{
if(a.is_true())
return tvt(true);
else if(a.is_false())
return tvt(false);
tvt result;
if(a.var_no()>=(unsigned)solver->model.size())
return tvt(tvt::TV_UNKNOWN);
using Minisat::lbool;
if(solver->model[a.var_no()]==l_True)
result=tvt(true);
else if(solver->model[a.var_no()]==l_False)
result=tvt(false);
else
return tvt(tvt::TV_UNKNOWN);
if(a.sign()) result=!result;
return result;
}
tvt satcheck_booleforce_baset::l_get(literalt a) const
{
assert(status==SAT);
if(a.is_true())
return tvt(true);
else if(a.is_false())
return tvt(false);
tvt result;
unsigned v=a.var_no();
assert(v<no_variables());
int r=booleforce_deref(v);
if(r>0)
result=tvt(true);
else if(r<0)
result=tvt(false);
else
result=tvt(tvt::tv_enumt::TV_UNKNOWN);
if(a.sign())
result=!result;
return result;
}
tvt boolector_propt::l_get(literalt a) const
{
tvt result=tvt(false);
std::string literal;
BtorExp *boolector_literal;
size_t found;
if(a.is_true())
return tvt(true);
else if(a.is_false())
return tvt(false);
literal_cachet::const_iterator cache_result=literal_cache.find(a.var_no());
if(cache_result!=literal_cache.end())
boolector_literal = cache_result->second;
else
return tvt(tvt::TV_UNKNOWN);
literal = boolector_bv_assignment(boolector_ctx, boolector_literal);
found=literal.find("1");
if (found!=std::string::npos)
result=tvt(true);
else
result=tvt(false);
if (a.sign()) result=!result;
return result;
}
void smt1_propt::set_assignment(literalt literal, bool value)
{
if(literal.is_true() || literal.is_false()) return;
unsigned v=literal.var_no();
assert(v<assignment.size());
assignment[v]=tvt(value);
}
tvt smt1_propt::l_get(literalt literal) const
{
if(literal.is_true()) return tvt(true);
if(literal.is_false()) return tvt(false);
unsigned v=literal.var_no();
if(v>=assignment.size()) return tvt(tvt::TV_UNKNOWN);
tvt r=assignment[v];
return literal.sign()?!r:r;
}
literalt aig_prop_baset::lselect(literalt a, literalt b, literalt c)
{ // a?b:c = (a AND b) OR (/a AND c)
if(a.is_true()) return b;
if(a.is_false()) return c;
if(b==c) return b;
// This produces unnecessary clauses and variables
// See convert_node for where this overhead is removed
return lor(land(a, b), land(neg(a), c));
}
tvt qbf_squolem_coret::l_get(literalt a) const
{
if(a.is_true())
return tvt(tvt::TV_TRUE);
else if(a.is_false())
return tvt(tvt::TV_FALSE);
else if(squolem->modelIsTrue(a.var_no()))
return tvt(tvt::TV_TRUE);
else if(squolem->modelIsFalse(a.var_no()) ||
squolem->modelIsDontCare(a.var_no()))
return tvt(tvt::TV_FALSE);
else
return tvt(tvt::TV_UNKNOWN);
}
void aigt::output_dot_edge(
std::ostream& out,
nodest::size_type v,
literalt l) const
{
if(l.is_true())
{
out << "TRUE -> " << v;
}
else if(l.is_false())
{
out << "TRUE -> " << v;
out << " [arrowhead=odiamond]";
}
else
{
out << l.var_no() << " -> " << v;
if(l.sign()) out << " [arrowhead=odiamond]";
}
out << "\n";
}
tvt satcheck_smvsatt::l_get(literalt a) const
{
assert(status==SAT);
if(a.is_true())
return tvt(true);
else if(a.is_false())
return tvt(false);
tvt result;
unsigned v=a.var_no();
switch(sat_instance_value(satsolver, v))
{
case 0: result=tvt(false); break;
case 1: result=tvt(true); break;
default: result=tvt(tvt::tv_enumt::TV_UNKNOWN); break;
}
if(a.sign()) result=!result;
return result;
}
tvt satcheck_minisat1_baset::l_get(literalt a) const
{
if(a.is_true())
return tvt(true);
else if(a.is_false())
return tvt(false);
tvt result;
assert(a.var_no()!=0);
assert(a.var_no()<(unsigned)solver->model.size());
if(solver->model[a.var_no()]==l_True)
result=tvt(true);
else if(solver->model[a.var_no()]==l_False)
result=tvt(false);
else
result=tvt(tvt::TV_UNKNOWN);
if(a.sign()) result=!result;
return result;
}
literalt bv_utilst::full_adder(
const literalt a,
const literalt b,
const literalt carry_in,
literalt &carry_out)
{
#ifdef OPTIMAL_FULL_ADDER
if(prop.has_set_to() && prop.cnf_handled_well())
{
literalt x;
literalt y;
int constantProp = -1;
if(a.is_constant())
{
x = b;
y = carry_in;
constantProp = (a.is_true()) ? 1 : 0;
}
else if(b.is_constant())
{
x = a;
y = carry_in;
constantProp = (b.is_true()) ? 1 : 0;
}
else if(carry_in.is_constant())
{
x = a;
y = b;
constantProp = (carry_in.is_true()) ? 1 : 0;
}
literalt sum;
// Rely on prop.l* to do further constant propagation
if(constantProp == 1)
{
// At least one input bit is 1
carry_out = prop.lor(x, y);
sum = prop.lequal(x, y);
}
else if(constantProp == 0)
{
// At least one input bit is 0
carry_out = prop.land(x, y);
sum = prop.lxor(x, y);
}
else
{
carry_out = prop.new_variable();
sum = prop.new_variable();
// Any two inputs 1 will set the carry_out to 1
prop.lcnf(!a, !b, carry_out);
prop.lcnf(!a, !carry_in, carry_out);
prop.lcnf(!b, !carry_in, carry_out);
// Any two inputs 0 will set the carry_out to 0
prop.lcnf(a, b, !carry_out);
prop.lcnf(a, carry_in, !carry_out);
prop.lcnf(b, carry_in, !carry_out);
// If both carry out and sum are 1 then all inputs are 1
prop.lcnf(a, !sum, !carry_out);
prop.lcnf(b, !sum, !carry_out);
prop.lcnf(carry_in, !sum, !carry_out);
// If both carry out and sum are 0 then all inputs are 0
prop.lcnf(!a, sum, carry_out);
prop.lcnf(!b, sum, carry_out);
prop.lcnf(!carry_in, sum, carry_out);
// If all of the inputs are 1 or all are 0 it sets the sum
prop.lcnf(!a, !b, !carry_in, sum);
prop.lcnf(a, b, carry_in, !sum);
}
return sum;
}
else // NOLINT(readability/braces)
#endif // OPTIMAL_FULL_ADDER
{
// trivial encoding
carry_out=carry(a, b, carry_in);
return prop.lxor(prop.lxor(a, b), carry_in);
}
}
